TeleGeography: Ethernet VPLS, EoDWDM interest grows, while IP/VPN expansion dips
HISTORICAL SPACE FREQUENCIES. The first satellite to orbit the Earth was Sputnik 1, launched by the Soviets in October 1957. It carried two radio beacons on frequencies of 20.005 and 40.01 MHz. The Soviets continued to use frequencies around 20 MHz and even some around 15 MHz for many subsequent missions. This tends to be used for uplinks of the satellites that downlink in the 137 - 138 MHz band. 2  149.95 - 150.05 MHz. 3  This is used by satellites providing positioning, time and frequency services, by ionospheric research and other satellites.
Some satellites revolve around the earth in elliptical orbits. These satellites move rapidly when they are near perigee, or their lowest altitude; they move slowly when they are near apogee, or their highest altitude. A satellite in low earth orbit circles the earth 100 to 300 miles above the earth's surface.Because it is close to the earth, it must travel very fast to avoid being pulled out of orbit by gravity and crashing into the earth. Satellites in low earth orbit travel about 17,500 miles per hour.he satellite is moving much faster than the earth's surface, though, because it must cover much more distance in the same amount of time. A geosynchronous satellite is moving at about 3.07 km/sec. Lower orbits are much faster.